There are many polarized lenses for driving in the market. Most of people may have a question, is this different from the general polarized lenses?
Let’s review the principle of polarized lenses. Polarized lenses incorporate a polarizing film in the general lenses. Duo to polarization principle, the polarizing film will prevent horizontal light from entering, only allowing vertical light to enter into the eyes. So that the objects will not be distorted by reflected or refracted light, and will make the outline and color of the object clearer and higher contrast. Besides, too much reflected light enter the eyes can cause the eyes being fatigue easily. The eyes will feel uncomfortable while wearing for a long time. Using good polarized lenses can make the eyes with relatively lower pressure, increasing the overall vision clearer.
( Source：American Academy of Ophthalmology)
Why polarized lenses are the most suitable for driving, because when driving, there are many high-intensity reflection from road or buildings, even the light from opposite cars. The reflective or horizontal light can easily affect the sight of driving line, resulting in blocking the road of condition in front of you. If driving for a long time, it also will reduce the fatigue of the eyes. Therefore, if you wear polarized lenses while driving, you can improve the dazzling glare and filter the messy light into single direction. Most of the important is raising the safety of driving.
Is it suitable for use at night or dark?
Since the polarized lens is a polarizing film added with the general lens, the light transmittance of lens itself has been lowered first. And the light of parallel portion is blocked when the light passes through the polarizing film, the light can be received is reduced. According to the natural reaction of human, when the light is insufficient or at night, the pupil will be enlarged to increase the amount of light. Once the pupil is enlarged, it will increase the degree of use of muscles of the eye. The eyes will feel exhausted soon. The resulting field of view becomes blurred. So it is not recommended to wear polarized sunglasses at night or when there is insufficient light, even if the back color of lens is yellow.
What we mentioned at the beginning – The driving special polarized lens. Not only adding a polarizing film, this kind of lens is also fused with the lens color changing technology which is a so called photochromic lens. It changes the color and light transmittance of lens according to the intensity of ultraviolet light. When used in a low light source environment, the photochromic lens will change from dark to transparent and the light transmittance will be from low to high. Combining with polarization and photochromic technology, it will not affect the line of vision due to external environment while wearing. So it is suitable for wearing during the day or at night. Related photochromic techniques will be demonstrate on next article.